Block-signal system



Feb. 26, 1929.

M. H. HOVEY BLOCK SIGNAL SYSTEM Filed May 18. 1927 INVENTOR.

ATTORNEY W XW Patented Feb. 26, 1929.

UNITED STATES MARK H. HOVEY, 01' MADISON, WISCONSIN.

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Application filed llayl'B,

This invention relates to railway signalling, particularly to railway electrical signalling, and more especially to that type of railway electrical signalling known as block signal systems.

A principal object of this invention, is to provide a means whereby a permissive indication may be given to a following train which approaches the entrance to a block section while a preceding train moving in the same direction is within the block limits, and whereby an absolutestop signal will be given to a train approaching the entrance to a single track block section when another train has entered the single track block section moving in a direction opposite to the direction of movement of the first train.

Other objects and advantages will appear as the description of the particular physical embodiment selected to illustrate the invention progresses, and the novel features of the invention will be particularly pointed out in the appended claims.

In describing the invention in detail and the particular physical embodiment selected to illustrate the principle of the invention, reference will be had to the accompanying drawing consisting of a single figure wherein the several parts are designed by characters of reference and which illustrates in a diagrammatic manner, a. portion of railway track equip ed with a. device embodying the principle 0' the invention.

In the drawing, the numeral 1 designates one rail of a railway track and numeral 2 designates the other rail thereof. The

' trackway is divided in accordance with common and wellknown practice, by means of the insulating joints 3, 4, 5, 6, 7 and 8 into thei electrically. isolated sections 9, 10, 11 an 12.

In practice, each of the sections would be similarily equippedwith what is known as a track circuit which would include a battery connected across the rails at one end of a section and a relay connected across the rails at the other end of the same sec-. tion. In the drawings, section '11 is equipped with the battery 13 at one end of the section and with the relay 14 at the other end of the section. Section 10 is equipped with the battery 15 and the relay 1c. v

The track circuit sections operate in the ordinary and well-known manner, that is,

aa'r. Serial no. mama.

when no train is upon the rails constituting part of the trackcircuit section, then the relay connected to that section is de-energized.

For governing trafiic over the section inone direction; applicant has illustrated a signal 16 which in accordance with approved light signal of commercial practice is intended to be indicated. p

In order to furnish the necessary electrical energy, for operating the devices included in the various circuits, applicant has provided sources of energy herein shown as batteries 20 and 21.

By means of the devices and circuits illustrated in the figure, it is intended that the track relays 14 and .16 operated automatically by the passage over several track circuit sections of trams, will cause the proper operation of the lamp 17, 18 and 19, so that when no train whatsoever is present either upon track section 19 or track section 11, then the green light 17 will be displayed. If a train is either upon track circuit section 10, or track circuit section 11, moving in the direction of the arrow 22, then the yellow light 18 will be displayed; if a train is either upon track circuit section 10 or track circuit section 11, moving in the direction of the arrow 23, then the red light 19 will be displayed. The meaning of these lights is as follows: A green light displayed means full clear ahead, no train in the sections; the yellow light displayed means proceed prepared to find a train either in section 10 or section 11, moving in the direction of the.

arrow 22; when the red light is displayed, the meaning is that a train is either on section 10 or section 11, moving. in the directionof the arrow 23. It is understood, that only the trains moving in the direction of the arrow 22, are to accept the indications of the signal 16 as is well understood by those skilled in the art. I I

When no train is either upon track circuit section 10 or track circuit section '11, both relays 14 and 16 are energinod, and'thoir ar break the circuit includin tion as shoyvn, then a circuit is formed which' lights the green lamp 17 as follows: positive terminal of battery 20, wires 37 and 38, armature 35, wire 39, lamp 17 and wires 39, 40, 41, 31, 32 and 42 to the negative terminal of the battery 20. Current flowing in the above traced path, causes the lamp 17 to be lighted and to emit a green light indicating that both track circuit sections 10 and 11 are unoccupied.

If while the relays are in the normal condition as shown in the figure,a train moving in the directionot' the arrow 22, should approach the signal 16, accept the green signal and enter upon the track circuit sec tion 10, then the first action would be the deenergization of relay 16, and the dropping of armature 25 which would immediatel break the'circuit, hereinbeiore traced, which controls relay 29, so that armature 35 would immediately drop, as would also armature 36. The dropping of armature 35 would inbefore traced, and so the lamp would be extinguished. As the train which caused lamp 17 to be extinguished, is moving in the direction of arrow 22, it is desired that a permissivesignal be established at signal 16 by this train, in order that a following train may proceed into section 10 and perhaps into section 11, so keeping following trains as close together as their speed permits. In order to provide a means for automatically exhibiting this desired permissive signal, applicant has provided amongst other things, an additional relay 43 and circuits therefor all as arranged that upon the entrance of a train into track circuit section 10 when moving in the direction of the arrow 22, a yellow light caused by lamp 18 would be exhibited. In order to do this, applicant provides first a circuit whereby relay 43, which applicant will denominate adirectional relay, is normally energized when no train is either upon track circuit sections 10 or 11, by current flowing in a path as follows: positive terminal of battery 20, wires 37 and 44, relay 43, wires 45, 46 and 47, resistance 48, wires 49 and 50, armature 36 and wires 51, 32, and 42 to the negative terminal of the'battery 20. Current flowing in the above traced path maintains relay 43 energized and so maintains its armatures 52 and 53 in the upper the lamp 17 here-.

position as shown. When a train moving in the direction of the arrow 22 into track circuit section 10, the relay 29 is deenergized as hereinbefore described, and relay armature 36 together with 35 drop to the, lower position. Armature 35 breaks the circuit of the green lamp 17 and, armature 36 breaks the maintaining circuit of relay 43, so that armatures 52 and 53 would naturally drop, unless something occurs to prevent such dropping. Applicant has provided a means whereby directional relay 43 is not deenergized by the entrance of a train onto track circuit section 10, when moving in the direction of the arrow 22. This includes the armature 54 of relay 16. \Vhen a train moving in the direction of the arrow 22, moves upon the track circuit section 10, the relay 16, as hereinbefore described is (leener 'zed, and when armature 25 drops, to brea: the circuit of relay 29, armature 54 drops to complete a circuit for directional relay 43, which circuit is as follows: positive terminal of battery 20, wires 37 and 44, directional relay 43, wire 45, resistance 55, wires 56 and 57, armature 54 and wires 58, 33 and 42 to the negative terminal of battery 20. The circuit last above traced is com leted before the armatures 52 and 53 fall away, due to the deenergization of relay 29 and the subsegluent dropping of armature 36. Current owing through the directional relay 43, in the path including the resistance 55, is suffi-' cient to maintain-the armatures 52 and 53 in their upper positions if the are already in that position, but is not su cient to raise them to the upper position if they are in the lower position.

It will be found then-that if a train is upon track circuit section 10, having entered that section moving in the direction of the arrow 22, that although relay 29 is de-energized and armature 35 dropped, relay 43 will be energized and armature 53 in the upper position, so that a circuit is formed in which current flows as follows: positive terminal of battery 20, wires 37 and 38, armature 35, wire 59, armature 53,

wire 60, lamp 18 and wires 61, 40, 41, 31, 32 and 42 the negative terminal of battery 20. The current flowing in the above traced path will cause the lamp 18 to emit a yellow light, which yellow light, known as a permissive signal, will inform a following train approaching the signal 16 while moving in the direction of the arrow 22., that a preceding train is either upon track circuit section 10 or track circuit section 11. been shown how the energization of relay 43 is maintained by a train upon section 10. In regard to section 11, it will be observed that if the supposed train moving in the direction of the arrow 22, passes upon section 11 from section 10, then relay 14 will be de-energized and armature 24 will. fall maintaining deenergization of relay 29, and consequently, relay armatures 35 and 36 in their lower position, and relay armature 36 direction of the arrow 22 is either. u on track circuit sections 10 or 11, the yel ow lamp 18 will be lighted giving the yellow indication at the signal 16. 2

Not only will the first following train receive a yellow indication at the signal 16, but all subsequent following trains just so long as any preceding train is in either track circuit section 10 or 11, because if a following train enters track circuit section 10 before a preceding train leaves track circuit section 10 or 11, then va relay16 will be maintained deenergized or rela 14 will be maintained deenergized, so that all of the time relay 29 would be deenergized, and directional relay 43 will be maintained energized b either or both of the circuits one of whic passes through armature 54, and the other of which passes through armature 36 when in the lower 'or deenergized position.

If a train approaches and enters upon track circuit section 11, when movin in the. direction of the arrow 23, while al of the parts are in the normal position as shown in the figure, then upon the deenergization of relay 14, the relay 29 will be come deenergized and its armatures 35 and 36 fall. During the time between the breaking of contact between armature 36 and: wire 50 and the closing of contact between armature 36 and wire 62, the directional relay 43 will become deenergized and its arma'tures 52 and 53 fall to their lower position. This is due to the fact that directional relay-43 is made very quick acting by including the resistance 48 in series with the maintaining circuit hereinbefore traced which includes the armature '36 when in the upper position. The inclusion of this resistance in such circuit, makes relay 43 so quick acting, that when armature 36 breaks contact with wire 50, the relay 43 becomes 3 so quickly deenergized, that armatures 52 and 53 will drop so quickly that b the time the armature 36 has reached an contacted with wire 62, the armatures 52 and 53 are out of range so far that the maintaining circuit closed through resistance 55 by the contacting of armature 36 with wire 62, will not bring the armatures back to the upper position so that the result is that the directional relay 43 becomes deenergized at the same time that relay 29 is deenergized, consequently, the circuit through the green lamp 17 is broken at armature 35, and the circuit for theyellow'l'ainp 18 is broken at armature 53 and the only circuit formed is that the red light 19 which is as follows: positive terminal of battery 20, wires 37 and 38, ar- 1 mature 35, wire 59, armature 53, wire 63, red lamp 19 and wires 64, 41, 31, 32 and 42 to the negative terminal of. battery 20. Current flowing in the last above traced path causes the red lamp 19 to be lighted thereby emitting a redlight' which indicates to atrain approaching signal '16 when moving in the direction of the arrow 22, that there is a train either upon section 10 or 11 moving in an opposite direction, that is, in the direction of the arrow 23. When the train moving in the direction of the arrow 23 maintains the deenergization of relay 29. v The deenergization of relay 16 and the dropping of armature 54 upon wire 57 does not however, energize directional 'relay 43 sufficiently to cause its armatures to be raised, because the resistance 55 is so adjust- .ed that the current flowing through relay 43 from source '20, when resistance 55 is in series therewith, is not suflicient to raise armatures 52 and 53 from their lower position, it is only sufiicient to maintain them in the raised position after they have once been raised by another circuit.

When the trainwhich we have been considering moving in the direction of the ,arrow 23, moves off from track circuit section- 10, then relays 14 and 16 are both energized. Relay 29 becomes \energized and armatures 35 and 36 are raised. When armature 36 is raised, at a time when directional relay 43 is deenergized a restoring circuit for directional relay 43 is formed as follows: positive terminal of battery 20,

terminal of the battery 20. Current flowing in the above traced path which has no resistance therein, other than the natural resistance, causes relay 43 to become energizedand moves the armature 52 and 53 to the upper position. When armature 52 moves to the up er position, it, of course, breaks contact with wire 65 and so breaks the last above described path through relay 43, but when armature- 52 has moved to such a position as to break that contact,-it is then in such a position that the hereinbefore described maintaining circuit through resistance 48 and armature 36 is capable of maintaining itin its then position.,

it will be understood that applicant has provided means whereby three signals may be displayed at the entrance to a sin le track block section. One of the signals, t 1e green, will be displayed when no train is u on any part of the track section governing t ereby; another, the yellow will be displayed to an approaching train which is moving in the same direction as a preceding train, when that preceding train or preceding trains have not yet moved entirely oil from the sections; a third, the red will be displayed when either or both of the track circuit sections are occupied by a train moving in a direction opposite to that of a train approaching the signal from the side from which the indication is received.

It is to be understood that applicant has illustrated and described a fundamental unit only. A means by which differently moving trains will difierently effect a signal by means automatic in its action. It will be understood that this unit will be applied in practice to the signalling of single track railways in such a manner as will provide the necessary arrangements for such roads when combined with those things which are well-known and thoroughly understood in the art and not necessary to be herein described, such as sequential polarized or unpolarized' line relays and simple pole changing relays.

Although applicant has herein described and illustrates one preferred physical em- 5 bodiment of his invention, and explained the principle, construction and operation thereof, nevertheless, it is desired to have it understood that the form selected is merely illustrative of a unit of a system and of one particular physical embodiment of the idea of means underlying the invention.

What I claim as new and desire to secure by Letters Patent of the United States, 1s:

1. In a railway signal system, in combination: a closed trackcircuit; a second closed track circuit; a normally closedcircuit; means controlled by the said normally closed circuit for signalling; means controlled by said track circuits for governing said normally closed circuit; a second normally closed circuit including a relay; means controlled by the first normally closed circuit to maintain the second normally closed circuit; a normally open circuit including the said relay; means for closing said normally.

open circuit controlled by the first mentioned track circuit and means controlled by the said relay for signalling.

2. In a railway signal system, in combination: a track circuited trackway; a normally closed circuit including a relay having armatures; means controlled by the trackcircuited trackway for governing said relay; means controlled by one of said relay armatures for signalling; a second normally closed circuit including a second relay having an armature and includingthe other of the armatures of the first mentioned relay; a normally open circuit including the second mentioned relay governed by a portion only of the track circui'ted trackway and means governed by said second relay for signalling.

' 3. In a railway signal system, in combina-' tion: a closed track circuit; a second closed track circuit; a normally closed circuit including a relay having armatures controlled by both of said track circuits; a second normally closed circuit including a resistance and a second relay having armatures and in .cluding an armature of the first mentioned relay; a normally open circuit including a resistance and the second mentioned relay and controlled by one only of the track circuits; a third normally closed circuit including an armature of the first mentioned relay the second mentioned relay and the second mentioned resistance; a third normally open circuit including an armature of the first mentioned relay, an armature of the second mentioned relay and the second mentioned relay closed when the first mentioned relay is energized and the second mentioned relay is deenergized, and means controlledby an r and a second -relayhaving armatures and including an armature of the first mentioned. relay; a normally open circuit including a resistance and the second mentioned relay and controlled by one only of the track circuits; a third normally closed circuit including an armature of the first mentioned relay the second mentioned relay and the second mentioned resistance and means controlled by an armature of said second mentioned relay for signalling.

5. In a railway signal system, in combination: a first and a second normally closed circuit; a normally open circuit; a first, second and a third signal; means for controlling the normally closed circuits and means for controlling the normally open circuit so that the first signal is operated when the first normally closed circuit is closed, the second signal when both normally closed circuits are open and the normally open circuit is closed and the third signal when both the normallyclosed circuits are 0 en and the normally 0 en circuit is open or as been closed only a r, the normally closed circuits have been opened. v

\ MARK'H. HOVEY. 

